• Journal of Information Technology Applications and Management
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• 제9권2호
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• pp.17-32
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• 2002

Even though the distance education via web has a great advantage to overcome time and space, its problem is that the management of trainees is not efficient compared with classroom and group education. This problem is a great obstacle to the objects and achievement standards of distance education, giving controversial arguments to the advocators of distance education. Distance educators need to monitor the trainees'participation and responses continuously and offer appropriate feedback to the trainees. However, the existing distance education system only focuses on teaching and learning activities, and as a result, the efficient management function of distance education is not available. Accordingly, the study attempts to find out the appropriate managing elements of distance teacher training in order to effectively achieve the goals of teacher training and the efficient management of distance education. Also, it proposes distance teacher training management system that offers appropriate feedback to trainees, applying the derived elements of distance teacher training to the training processes. To verify the efficiency of the system, hypotheses on related items of distance teacher education and learning types are suggested, and the achievement degree of learning and its relations are investigated through questionnaire of learning types. In addition, a system using UML which is the standard of object-oriented modeling language is devised, so. that mutual management, language independence and convenient development environment as well as reusability can be offered, and so the design standardization and efficient system realization could be achieved, while flexible change of system according to education process and computing environment is possible.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.219-224
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• 2002

This paper aims to derive a mathematical model of the dynamics of handling tasks in robot finger which stable grasping and manipulates a rigid object with some dexterity. Firstly, a set of differential equation describing dynamics of the manipulators and object together with geometric constraint of tight area-contacts is formulated by Lagrange's equation. Secondly, problems of controlling both the internal force and the rotation angle of the grasped object under the constraints of area-contacts of tight area-contacts are discussed. The effect of geometric constraints of area-contacts on motion of the overall system is analyzed and a method of computer simulation for overall system of differential-algebraic equations is presented. Thirdly, simulation results are shown and the effects of geometric constraints of area-contact is discussed. Finally, it is shown that even in the simplest case of dual single D.O.F manipulators there exists a sensory feedback from sensing data of the rotational angle of the object to command inputs to joint actuators and this feedback connection from sensing to action eventually realizes secure grasping of the object, provided that the object is of rectangular shape and motion is confined to a horizontal plane.

• 컴퓨터교육학회논문지
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• 제14권5호
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• pp.71-79
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• 2011

본 논문은 학습자들이 언제 어디서나 상호작용이 가능하고 실시간 피드백이 가능한 협동학습을 지원하는 시스템을 구현하였다. 구현된 앱을 스마트폰에 설치함으로써 사이트에 접속할 필요 없이 사용자가 글을 올리면 즉시 볼 수 있고 그것에 대한 피드백을 실시간으로 할수 있는 소셜네트워크 서비스 시스템이다. 개발된 소셜네트워크 서비스 프로그램은 학습자의 과제해결을 위해 실시간 소통의 매개체로 사용하였으며, 실시간 상호작용과 피드백으로 인한 학업성취도와 학습 흥미도를 높일 수 있다. 또한 축적된 자료를 바탕으로 교수자가 학습자의 수준을 세밀하게 파악하여 학습자에게 실제적 도움을 줄 수 있다.

• 한국통신학회논문지
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• 제27권7C호
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• pp.704-711
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• 2002

본 논문에서는 케이블 모뎀을 위한 DFE(Decision Feedback Equalizer) 구조의 blind 등화기를 설계하였다. 변복조 방식은 64/256 QAM이며 채널 적응 알고리즘으로는 제안한 MMA(Multi-Modulus Algorithm)와 LMS (Least Mean Square) 알고리즘을 같이 사용하였다. MMA 알고리즘과 DFE 구조를 가진 등화기는 본 논문에서 처음 제안한다. 기존의 MMA 등화기는 두 개의 FIR 필터를 사용하여 두 개의 탭 계수를 갱신하였으나, 본 논문에서 제안하는 MMA 알고리즘은 하나의 탭 계수 갱신만으로 채널 등화가 가능하도록 제안하였으며, DFE 구조에 적용하여 두 개의 DFE 필터를 사용하여 채널 적응 능력을 높히고 탭 수를 줄였다. 0.35 $\mu\textrm{m}$ standard cell library를 이용하여 ASIC 칩을 설계하였다. 설계한 등화기는 약 16만개의 게이트 수와 8 MHz의 동작속도를 보였으며 데이터 전송 속도는 64Mbps까지 지원한다.

• 정보처리학회논문지C
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• 제9C권6호
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• pp.953-960
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• 2002

실시간 응용 프로그램은 미디어 데이터간에 만족되어야 할 동기화 제약조건(synchronization constraints)을 가지고 있다. 멀티미디어 데이터의 가변적 전송 시연 시간을 흡수하여 피드백 제어와 재생정책에 의한 동기화 기법을 수행한다. 버퍼의 수위가 정상레벨을 유지하는가에 대한 문제는 재생률과 QoS 서비스에 중요한 영향을 주게 된다. 본 논문에서는 버퍼의 수위를 안정상태고 유지하기 위해 피트백을 위한 필터링함수를 적용하고, 재생시간을 적응적으로 적용하여 미디어의 재생 시 끊어짐이 없는 유연한 재생을 한다. 또한 버퍼의 주 미디어인 오디오 프레임의 버퍼가 상위임계레벨에 수위가 존재 할 경우는 적응적으로 재생시간을 줄이고, 하위임계레벨에 버퍼의 수위가 있을 경우는 점차적으로 재생시간을 늘리는 시스템이다.

• 한국항공운항학회지
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• 제21권3호
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• pp.9-14
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• 2013

Continuous airworthiness system is comprised of regulations and procedures to assure the safety and reliability through the total stage of development, certification and operation of aircraft. The purpose of this system is not only to provide the guidelines that should be kept by manufacturers and operators, but also to evaluate the maintenance capability in every activity of safety related procedures. During the development process of the mid and large size aircraft, operational experience should be reflected systematically for a safer and more reliable product by using the meaningful data base from operation. The relationship of safety roles between manufacturer and operator is mutually complementary, and the roles of each function have an influence to the next step. Overall structure of the procedure contains the concept of continuous analysis and feedback to achieve highest degree of safety and reliability during the entire life of aircraft. Finally, this paper describes how the feedback is made and used for aircraft design from operational experience under the continuous analysis and surveillance system.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1780-1787
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• 2014

Arterial oxygen saturation ($SpO_2$) monitoring for newborns requires special attention in neonatal intensive care units (NICUs). Newborns have very low photo-plethysmogram (PPG) amplitudes and their body movements are difficult to contain. Hardware design and its associated signal processing algorithms should be robust enough so that faulty measurements can be avoided. In this study, improved designs were implemented to deal with low perfusion, motion artifact, and the influence of ambient light. Dynamic range was increased by using different LED intensities and a feedback system. To minimize the effects of motion artifact and to discard other unqualified data, four additional algorithms were used, which were based on dual-trace detection, continuity of DC level, morphology of PPG, and simultaneity check of $SpO_2$. Our $SpO_2$ system was tested with newborns with normal respiration in the NICU. Our system provided fast, real-time responses and 100% artifact detection was accomplished under 84% of $SpO_2$.

• 한국의류산업학회지
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• 제21권4호
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• pp.401-411
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• 2019

Non-contact judgment and evaluation for products are increasingly needed along with a rapid environmental change in fashion that sows urgency in the need to implement services that allows users to judge and experience a tactile sense in a fashion product without actual contact. Technological development is required to provide users with syn-aesthetic experiences that integrate the visual, tactile and the auditory. There is also a need to conduct research to increase immersion that provides users with ICT-related experiences communicated through fashion images. The study analyzed demands for haptic communication technology by Korean users in immersive VR fashion product shopping. Accordingly, it defined haptic communication through literature research, investigated immersion in the VR environment and conducted in-depth interviews for haptic communication applicable to VR shopping. Findings show that hedonic reactions by fantasy, emotion and fun function are an important motive in selecting VR shopping. VR fashion product shopping steps were divided into 4: move to store, search in store, search of product and purchase based on offline store shopping experience. It defined the haptic communication by steps and analyzed the types of the haptic feedback to be implemented. The study results provide basic data for developing haptic communication technology that can enhance e a sense of the presence and immersion experiences that can help lay a groundwork for pilot studies on the convergence of the virtual and the real.

• Nuclear Engineering and Technology
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• 제51권7호
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• pp.1721-1728
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• 2019

The advanced node core code CORCA-3D is one of the independent developed codes of NPIC for the nuclear reactor core design. CORCA-3D code can calculate the few-group cross section, solve the 3D diffusion equations, consider the thermal-hydraulic feedback, reconstruct the pin-by-pin power. It has lots of functions such as changing core status calculation, critical searching, control rod value calculation, coefficient calculation and so on. The main theory and functions of CORCA-3D code are introduced and validated with a lot of reactor measured data and the SCIENCE system. Now, CORCA-3D code has been applied in ACP type reactor nuclear cores design.

• 패션비즈니스
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• 제24권6호
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• pp.135-147
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• 2020

This study explored students' online fashion studio class experiences, and investigated the factors affecting their class satisfaction. An online survey of college students who were enrolled in online studio classes within apparel and fashion-related departments during the spring of 2020 was conducted in June 2020. Responses from a total of 213 participants were included in the final data. Respondents rated lecture clips as the most useful, followed by teacher demonstration and feedback, PowerPoint (PPT) supplements, and Q&As. Frequently mentioned areas of improvement were online platform stability and video quality. Many respondents also stated that more streamlined teacher-student communication channels, immediate and meticulous teacher feedback, the adoption of course contents developed specifically for an online environment, and provisions for equipment usage would be desirable. Student satisfaction of an online fashion design studio class was significantly affected by teaching presence, social presence, online learning system stability, perceived usefulness of teacher's demonstration, and affective response toward COVID-19. Students satisfaction of an online garment construction studio class was significantly affected by teaching and social presence, online learning system stability, and perceived usefulness of teacher's demonstration. Based on these findings, we recommend developing teaching contents and methods that allow students to feel included in class and establish an online system with various functions to enhance the sense of social connection that can enable two-way communication.